An animal model of stress-induced hypertension has been developed, which combined genetic manipulations with psychological stress. Stress in these animals (with spontaneous borderline hypertension) pushes pressures well up into the hypertensive range. Termination of stress for a ten week period following a twelve week exposure to conflict does not reduce blood pressure to control levels. Stressed animals have a greater incidence of elevated heart weight/body weight ratios, and myofibrillar degeneration and fibroblast infiltration than control subjects. Research during the next year seeks to replicate this finding. We will also be studying the pathological response of the animals in more detail.